Whats wrong with this adapter, when i scroll down i see repeated rows at the bottom and then when scroll up again i see also repeated rows at the top that were not exist before, and the rest of Data items does not appear
the adapter:
public class ClassesListViewAdapter extends BaseAdapter {
private Context mContext;
ArrayList<String> Data = new ArrayList<>();
public ClassesListViewAdapter(Context context, ArrayList<String> data) {
Data = data;
mContext = context;
}
#Override
public Object getItem(int position) {
return position;
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public int getCount() {
return Data.size();
}
private class ViewHolder{
TextView ClassDataTV;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = ((Activity)mContext).getLayoutInflater();
ViewHolder holder;
if (convertView == null) {
convertView = inflater.inflate(R.layout.classes_list_view_item, parent, false);
holder = new ViewHolder();
holder.ClassDataTV = (TextView) convertView.findViewById(R.id.ClassDataTV);
holder.ClassDataTV.setText(Data.get(position));
convertView.setTag(holder);
}else{
holder=(ViewHolder)convertView.getTag();
}
return convertView;
}
}
and here how i use it:
ArrayList<String> v = new ArrayList<>();
v.add("AAAAAAA");
v.add("WWWWWwW");
v.add("VVVVVVV");
v.add("SSSSSSSSS");
v.add("QQQQQQQQQ");
v.add("YYYYYYYY");
v.add("TTTTTTT");
v.add("UUUUUUUUUU");
v.add("zzzzzzzzzzzz");
v.add("CCCCCCCCCC");
v.add("HHHHHHHHHHH");
v.add("IIIIIIIIII");
v.add("PPPPPPPPP");
mListView.setAdapter(new ClassesListViewAdapter(getActivity(), v));
Put following part of your code outside if-block and it will be fixed :
#Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = ((Activity)mContext).getLayoutInflater();
ViewHolder holder;
if (convertView == null) {
convertView = inflater.inflate(R.layout.classes_list_view_item, parent, false);
holder = new ViewHolder();
holder.ClassDataTV = (TextView) convertView.findViewById(R.id.ClassDataTV);
convertView.setTag(holder);
}else{
holder=(ViewHolder)convertView.getTag();
}
// initialize your view here
holder.ClassDataTV.setText(Data.get(position));
return convertView;
}
The logic behind ViewHolder pattern tells that you should do it in this way. when you scroll some of reference will not created again and else block called so this cause your list not updated as you expected.
Related
I'm implementing a ListView with 2 TextViews in it. The first TextView is the name of the product that I'm populating from a query. When I touch any item in the ListView a Dialog appears. When I confirm the Dialog I would like to change the second TextView text to string but whenever I do so every second Textview text changes. For example, if I have 3 items in list view and I click the first one only that item's text view should change instead of all three.
This is my base adapter code:
public class StrengthAdapter extends BaseAdapter {
private ArrayList<Strengths> list;
private LayoutInflater layoutInflater;
private static HashMap<Integer, String> selectedStrengthsMap = new HashMap<Integer, String>();
private String testing;
public StrengthAdapter(Context context, ArrayList<Strengths> list, String test) {
this.list = list;
layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
this.testing = test;
//HashMap<Integer, String> issuesStrengthsbrandNameIDMap = context
}
#Override
public int getCount() {
return list.size();
}
#Override
public Object getItem(int position) {
return list.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
final ViewHolder viewHolder;
if (convertView == null){
viewHolder = new ViewHolder();
//viewHolder.position = position;
convertView = layoutInflater.inflate(R.layout.strengthslistview, null);
viewHolder.strengthCheckBox = (TextView) convertView.findViewById(R.id.strengthsCheckBox);
viewHolder.chip = convertView.findViewById(R.id.chip);
convertView.setTag(viewHolder);
}else {
viewHolder = (ViewHolder) convertView.getTag();
}
viewHolder.strengthCheckBox.setText(((Strengths) list.get(position)).getStrength_title());
viewHolder.chip.setText(testing);
//viewHolder.position = position;
return convertView;
}
public static HashMap<Integer, String> sendSelectedStrengthMap(){
return selectedStrengthsMap;
}
static class ViewHolder {
TextView strengthCheckBox;
TextView chip;
//int position;
}
}
This is how my I set my adapter initially:
strengthListView.setAdapter(new StrengthAdapter(StrengthOfDemandsView.this, strengthsList, "TEST"));
and this is how I set my adapter after closing the dialog:
builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int id) {
strengthListView.setAdapter(new StrengthAdapter(StrengthOfDemandsView.this, strengthsList, "TEST123"));
}
});
You need to handle clicks inside of your adapter and not setting adapter every time click happens. It have to look like this:
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
final ViewHolder viewHolder;
if (convertView == null){
viewHolder = new ViewHolder();
//viewHolder.position = position;
convertView = layoutInflater.inflate(R.layout.strengthslistview, null);
viewHolder.strengthCheckBox = (TextView) convertView.findViewById(R.id.strengthsCheckBox);
viewHolder.chip = convertView.findViewById(R.id.chip);
convertView.setTag(viewHolder);
}else {
viewHolder = (ViewHolder) convertView.getTag();
}
viewHolder.strengthCheckBox.setText(((Strengths) list.get(position)).getStrength_title());
convertView.setOnClickListener(
// show dialog here and then in positiveButton callback call
//viewHolder.chip.setText(testing);
);
return convertView;
}
First of all inflate your layout before creation of holder.
Then you need to define onclick behavior by implementing onclicklistener. I updated your getView method please implement this as follows:
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
final ViewHolder viewHolder;
if (convertView == null){
convertView = layoutInflater.inflate(R.layout.strengthslistview, null);
viewHolder = new ViewHolder();
//viewHolder.position = position;
viewHolder.strengthCheckBox = (TextView) convertView.findViewById(R.id.strengthsCheckBox);
viewHolder.chip = convertView.findViewById(R.id.chip);
convertView.setTag(viewHolder);
}else {
viewHolder = (ViewHolder) convertView.getTag();
}
viewHolder.strengthCheckBox.setText(((Strengths) list.get(position)).getStrength_title());
viewHolder.chip.setText(testing);
//viewHolder.position = position;
convertView.setOnClickListener(
//you can do your job here what u want to do by clicking specific row
);
return convertView;
}
Also write your functionalities in the block I mentioned above in comments.
I need to show multiple text views in only one list item and the rest of the list view items will have just one textview.
How do I achieve this? Any samples or tutorials you can point me at?
Thank you.
Make your own adapter:
BaseAdapter already provieds methods for working with different View types (different layout for list item cells) and to effektivly recycle views:
getViewTypeCount(): The count of how many different Views (layouts) are present.
getItemViewType(): Returns a integer to identify the view type of the item in the cell. Note the internally BaseAdapter implementation uses an array. Therefore your values returned here must be from 0 to n. You are not allowed to skip indexes.
public class MyAdapter extends BaseAdapter {
private final int VIEW_TYPE_NORMAL = 0;
private final int VIEW_TYPE_4_TEXTS = 1;
/**
* The inflater for
*/
protected LayoutInflater inflater;
protected Context context;
public MyAdapter(Context context) {
this.context = context;
this.inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
#Override
public int getViewTypeCount() {
// There are two view types
return 2;
}
#Override
public int getItemViewType(int position) {
if (position == 0)
return VIEW_TYPE_4_TEXTS;
else
return VIEW_TYPE_NORMAL;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
int type = getItemViewType(position);
if (convertView == null) {
convertView = newView(type, parent);
}
bindView(position, type, convertView);
return convertView;
}
#Override
public long getItemId(int position) {
return 0; // replace it with your id, if you have stable ids in your
// adapter
}
/** Inflates the correct view accorind the view type **/
public View newView(int type, ViewGroup parent) {
if (VIEW_TYPE_4_TEXTS == type) {
View view = inflater.inflate(R.layout.your_layout_with_4_textviews,
parent, false);
view.setTag(new ViewHolder4TextViews(view)); // ViewHolder pattern
return view;
}
// Otherwise its a normal item with VIEW_TYPE_NORMAL
View view = inflater
.inflate(R.layout.your_normal_layout, parent, false);
view.setTag(new NormalViewHolder(view)); // ViewHolder pattern
return view;
}
/** Bind the data for the specified {#code position} to the {#code view}. */
public void bindView(int position, int type, View view) {
if (VIEW_TYPE_4_TEXTS == type) {
// set the 4 text view values
ViewHolder4TextViews holder = (ViewHolder4TextViews) view.getTag();
holder.textview1.setText("...");
holder.textview2.setText("...");
holder.textview3.setText("...");
holder.textview4.setText("...");
} else {
// VIEW_TYPE_NORMAL
NormalViewHolder holder = (NormalViewHolder) view.getTag();
holder.textview.setText("...");
}
}
}
Use a custom adapter for you list and edit the getView function:
public class MyListAdapter extends BaseAdapter {
[...]
#Override
public View getView(int position, View view, ViewGroup parentView) {
LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if(position < 1) {
/* Inflate a layout with 4 textview */
view = inflater.inflate(R.layout.your_4_textview_layout, parentView, false);
} else {
/* Inflate a layout with 1 textview */
view = inflater.inflate(R.layout.your_1_textview_layout, parentView, false);
}
return view;
}
[...]
}
Take care about pass Context context to MyListAdapter in constructor like this answer
You can make changes in your adapter...some thing like this.
#position 1: "blank" view will be diplayed
#rest positions: "triplistrow" will bw displayed
#Override
public View getView(final int position, View convertView, final ViewGroup parent)
{
View rowView = convertView;
if(position !=1)
{
if (rowView == null)
{
LayoutInflater inflater = context.getLayoutInflater();
rowView = inflater.inflate(R.layout.triplistrow, null);
ViewHolder viewHolder = new ViewHolder();
viewHolder.no = (TextView) rowView.findViewById(R.id.TVTripNo);
viewHolder.name = (TextView) rowView.findViewById(R.id.TVTripName);
viewHolder.date = (TextView) rowView.findViewById(R.id.TVTripDate);
rowView.setTag(viewHolder);
}
}
else
{
LayoutInflater inflater = context.getLayoutInflater();
rowView = inflater.inflate(R.layout.triplistrow, null);
ViewHolder viewHolder = new ViewHolder();
rowView.setTag(viewHolder);
}
if(position!=1)
{
final ViewHolder holder = (ViewHolder) rowView.getTag();
holder.no.setText(String.valueOf(position+1));
holder.name.setText(values.get(position).name);
holder.date.setText(values.get(position).fromdate + " to " + values.get(position).tilldate);
}else
{
}
return rowView;
}
I am creating a custom list view using baseadapter.i have 10 list item in my list.my problem is that afetr 6 items ,the first 4 are repeating.i just printed position values in getview.it gives 0,1,2,3,4,5,6,7,8,9,0,1,2,3.My code is below.
thanx in advance
public class ProductListAdapter extends BaseAdapter implements OnClickListener{
/*
* developer :sanu
* date :10-4-2013
* time :3.34 pm
*/
public View row;
private String[] productName;
private String[] producttype;
private String[] priceRangeFrom;
private String[] priceRangeTo;
private String[] productImage;
private Activity activity;
private static LayoutInflater inflater=null;
static String posClicked;
ViewHolder holder;
Integer height1;
Integer width1;
Typeface tf;
Integer FirmaCount;
public ImageLoader imageLoader;
public ProductListAdapter(Activity a,String[] name,String[] type,String[] price_from,String[] price_to,String[] image,Typeface tf) {
activity = a;
productName = name;
producttype = type;
priceRangeFrom = price_from;
priceRangeTo = price_to;
productImage = image;
inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
imageLoader=new ImageLoader(activity.getApplicationContext());
}
public int getCount() {
return productName.length;
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public int getViewTypeCount (int position)
{
return position;
}
public static class ViewHolder{
public TextView nameProduct;
public TextView typeProduct;
public TextView priceRangeProduct;
public ImageView productImage;
public ImageView plusImage;
public RelativeLayout mainLayout;
public int position;
}
public View getView(int position, View convertView, ViewGroup parent) {
if(convertView == null){
convertView = inflater.inflate(R.layout.product_list_details,parent, false);
holder=new ViewHolder();
holder.nameProduct =(TextView)convertView.findViewById(R.id.name);
holder.typeProduct =(TextView)convertView.findViewById(R.id.product);
holder.priceRangeProduct =(TextView)convertView.findViewById(R.id.pricerange);
holder.productImage =(ImageView)convertView.findViewById(R.id.image);
holder.plusImage =(ImageView)convertView.findViewById(R.id.dot);
holder.mainLayout = (RelativeLayout)convertView.findViewById(R.id.mainlayout);
holder.nameProduct.setText(productName[position]);
if(producttype[position].length()>18)
{
holder.typeProduct.setText(producttype[position].substring(0,18)+"...");
}
else
{
holder.typeProduct.setText(producttype[position]);
}
holder.priceRangeProduct.setText(priceRangeFrom[position].substring(0,priceRangeFrom[position].length()-2)+" To "+priceRangeTo[position].substring(0, priceRangeTo[position].length()-2));
imageLoader.DisplayImage(productImage[position], holder.productImage);
convertView.setTag(holder);
}
else
{
holder = (ViewHolder)convertView.getTag();
}
holder.plusImage.setTag(Integer.toString(position));
holder.plusImage.setOnClickListener(this);
holder.mainLayout.setTag(Integer.toString(position));
holder.mainLayout.setOnClickListener(this);
return convertView;
}
This sounds like a case of View re-cyclcing. Android will pass a pre-populated view to the getView method. It does so to minimize object creation. When an existing row-view is scrolled off screen, Android might try to recycle that view to display a row that is now on-screen. You need to account for the fact that this view may have been used to display data for another row (which is now off screen).
You have the following line
holder.typeProduct.setText
within the following conditional:
if(convertView == null){
Move that line outside of the conditional, and all should be well.
It's like EJK said. You are not recycling your view correctly. Change your code to this and notice where I put the setText calls
public View getView(int position, View convertView, ViewGroup parent) {
if(convertView == null){
convertView = inflater.inflate(R.layout.product_list_details,parent, false);
holder=new ViewHolder();
holder.nameProduct =(TextView)convertView.findViewById(R.id.name);
holder.typeProduct =(TextView)convertView.findViewById(R.id.product);
holder.priceRangeProduct =(TextView)convertView.findViewById(R.id.pricerange);
holder.productImage =(ImageView)convertView.findViewById(R.id.image);
holder.plusImage =(ImageView)convertView.findViewById(R.id.dot);
holder.mainLayout = (RelativeLayout)convertView.findViewById(R.id.mainlayout);
convertView.setTag(holder);
}
else
{
holder = (ViewHolder)convertView.getTag();
}
holder.plusImage.setTag(Integer.toString(position));
holder.plusImage.setOnClickListener(this);
holder.mainLayout.setTag(Integer.toString(position));
holder.mainLayout.setOnClickListener(this);
//setText functions are here
holder.nameProduct.setText(productName[position]);
if(producttype[position].length()>18)
{
holder.typeProduct.setText(producttype[position].substring(0,18)+"...");
}
else
{
holder.typeProduct.setText(producttype[position]);
}
holder.priceRangeProduct.setText(priceRangeFrom[position].substring(0,priceRangeFrom[position].length()-2)+" To "+priceRangeTo[position].substring(0, priceRangeTo[position].length()-2));
imageLoader.DisplayImage(productImage[position], holder.productImage);
return convertView;
}
Change your getView to
public View getView(int position, View convertView, ViewGroup parent) {
if(convertView == null){
convertView = inflater.inflate(R.layout.product_list_details,parent, false);
holder=new ViewHolder();
holder.nameProduct =(TextView)convertView.findViewById(R.id.name);
holder.typeProduct =(TextView)convertView.findViewById(R.id.product);
holder.priceRangeProduct =(TextView)convertView.findViewById(R.id.pricerange);
holder.productImage =(ImageView)convertView.findViewById(R.id.image);
holder.plusImage =(ImageView)convertView.findViewById(R.id.dot);
holder.mainLayout = (RelativeLayout)convertView.findViewById(R.id.mainlayout);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.nameProduct.setText(productName[position]);
if(producttype[position].length()>18)
{
holder.typeProduct.setText(producttype[position].substring(0,18)+"...");
}
else
{
holder.typeProduct.setText(producttype[position]);
}
holder.priceRangeProduct.setText(priceRangeFrom[position].substring(0,priceRangeFrom[position].length()-2)+" To "+priceRangeTo[position].substring(0, priceRangeTo[position].length()-2));
imageLoader.DisplayImage(productImage[position], holder.productImage);
holder.plusImage.setTag(Integer.toString(position));
holder.plusImage.setOnClickListener(this);
holder.mainLayout.setTag(Integer.toString(position));
holder.mainLayout.setOnClickListener(this);
return convertView;
}
Also check this
How ListView's recycling mechanism works
Change getView()
Declare ViewHolder before if (convertView == null)
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = inflater.inflate(R.layout.product_list_details,
parent, false);
holder = new ViewHolder();
holder.nameProduct = (TextView) convertView.findViewById(R.id.name);
holder.typeProduct = (TextView) convertView
.findViewById(R.id.product);
holder.priceRangeProduct = (TextView) convertView
.findViewById(R.id.pricerange);
holder.productImage = (ImageView) convertView
.findViewById(R.id.image);
holder.plusImage = (ImageView) convertView.findViewById(R.id.dot);
holder.mainLayout = (RelativeLayout) convertView
.findViewById(R.id.mainlayout);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.nameProduct.setText(productName[position]);
if (producttype[position].length() > 18) {
holder.typeProduct.setText(producttype[position].substring(0, 18)
+ "...");
} else {
holder.typeProduct.setText(producttype[position]);
}
holder.priceRangeProduct.setText(priceRangeFrom[position].substring(0,
priceRangeFrom[position].length() - 2)
+ " To "
+ priceRangeTo[position].substring(0,
priceRangeTo[position].length() - 2));
imageLoader.DisplayImage(productImage[position], holder.productImage);
holder.plusImage.setTag(Integer.toString(position));
holder.plusImage.setOnClickListener(this);
holder.mainLayout.setTag(Integer.toString(position));
holder.mainLayout.setOnClickListener(this);
return convertView;
}
I have an ArrayAdapter with ArrayList filled. Each time I click on any of its item I re-fill the ArrayList and send notifyOnDataSetChange() to the adapter. But for unknown for me reason it goes out of ArrayList bounds in it's getView() method where it populates its items. I don't understand why this happens. Can you guys explain the theory of getView() invokation so I understand why this going on. Thanks in advance!
Here it is:
class MAdapter extends ArrayAdapter<String> {
public MAdapter(Context context, int textViewResourceId, List<String> objects) {
super(context, textViewResourceId, objects);
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
if (v == null) {
LayoutInflater vi = (LayoutInflater) getActivity().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.file_explorer_row, null);
} else {
}
String txt = itemsList.get(position); // Out of bounds happens here
if (!txt.equals("")) {
TextView tt = (TextView) v.findViewById(R.id.file_explorer_tv_filename);
tt.setText(txt);
}
return v;
}
itemsList is declared in Outer Class.
change like this
public View getView(int position, View convertView, ViewGroup parent) {
View view = convertView;
if (view == null)
{
LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = inflater.inflate(R.layout.file_explorer_row, parent, false);
}
Though i am not getting a clear view of what you are asking..i am assuming that , you are refilling the entire ArrayAdapter again....
So try this.........
Use removeView() on ListView before setting the adapter to it...
Eg:
ListView.removeView();
ListView.setAdapter(yourAdapter);
String txt = itemsList.get(position);
itemsList.get(position) returns a Integer Value and that you are try to store in a String..this might be the reason.
Try this code:
class MAdapter extends BaseAdapter {
List<String> objects;
Context context;
public MAdapter(Context context,List<String> objects) {
super();
this.context=context;
this.objects=objects;
}
public int getCount() {
return objects.size();
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return 0;
}
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
Holder holder;
LayoutInflater vi;
if (v == null) {
holder=new Holder();
vi = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.file_explorer_row, null);
holder.tt= (TextView) v.findViewById(R.id.file_explorer_tv_filename);
v.setTag(holder);
} else {
holder = (Holder) v.getTag();
}
String txt = objects.get(position); // Out of bounds happens here
if (!txt.equals("")) {
holder.tt.setText(txt);
}
return v;
}
static class Holder{
TextView tt;
}
}
Simple but little tricky, if I have
list.setAdapter(new ArrayAdapter<String>(this,R.layout.double_row, R.id.doubleRow, articleItemsHelper));
it works if articleItemsHelper is String, but I wanna have HTML formatting in there so when articleItemsHelper is type Spanned this (adapter) doesn't work.
ArrayList<Spanned> articleItemsHelper = new ArrayList<Spanned>();
What's the solution?
EDIT: here is the solution - custom adapter
private static class SpannedAdapter extends BaseAdapter {
private LayoutInflater mInflater;
private ArrayList<Spanned> mArticleList;
public SpannedAdapter(Context context, ArrayList<Spanned> articleList) {
mInflater = LayoutInflater.from(context);
mArticleList = articleList;
}
public int getCount() {
return mArticleList.size();
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.single_row, null);
holder = new ViewHolder();
holder.text = (TextView) convertView.findViewById(R.id.singleRow);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.text.setText(mArticleList.get(position));
return convertView;
}
static class ViewHolder {
TextView text;
}
}
Then just regularly call
list.setAdapter(new SpannedAdapter(this, articleItemsHelper));
where
articleItemsHelper
is
ArrayList<Spanned>
Old thread but I found an other way to do it, it can help people:
simpleAdpt = new ArrayAdapter<Note>(this, R.layout.notelist, listeNotes ){
public View getView(int position, View view, ViewGroup viewGroup)
{
View v = super.getView(position, view, viewGroup);
Note n = (Note) this.getItem(position);
((TextView)v).setText(Html.fromHtml("<b>"+n.getTitre() + "</b> <br/>"+n.getNote()));
return v;
}
};
This is how ArrayAdapter set the text of the rows:
T item = getItem(position);
if (item instanceof CharSequence) {
text.setText((CharSequence)item);
} else {
text.setText(item.toString());
}
As you can see, what it would do in your case is to call the toString method, and that's why it does not work. So, go ahead and write your own adapter, you have no choice in this case.